Carburetor having idle fuel control means



A 9,1966 B. WALKER ETAL 3,265,373

CAREURETOR HAVING IDLE FUEL CONTROL MEANS 7 Filed May 7, 1962 United States Patent Kertell assiguor to said Walker Filed May 7, 1962, Ser. No. 192,873 2 Claims. (Cl. 261-41) This invention pertains to means for controlling the fuel to an internal combustion engine and pertains particularly to the operation at closed throttle idle conditions and closed throttle deceleration conditions when it may be desirable to cut off the idle fuel during such deceleration :at engine speeds above idle engine speed.

The Hoof US. Patent 2,221,936, issued August 27, 1940, shows a slide valve 68a in FIG. 6 for shutting off the idle fuel to passage 32 leading to idle jets 40, see FIGS. 3 and 4. Such a slide valve, if used to shut off the idle fuel directly, will leak fuel past said slide valve under the high suction present at the idle jet during deceleration. In order to utilize a single rod to control two paths of idle fuel to two idle jets, this invention introduces a ball valve and an elastic seat such as a neoprene O ring with the two balls unseated by a single control whether solenoid or diaphragm to control the flow of fuel to the idle jets and provide a positive shut off at two points with a single powered control.

A sliding valve such as in said Hoof reference is more likely to introduce fuel or air leakage than a rotating control rod on the upstream side of the ball seat such as applicant uses, so another feature is the use of a partially rotating rod to operate separate valves to positively shut off fuel flow to two idle jets.

Another feature is to use balls and cams on the up stream side of the ball seats so that the cams are not subjected to high engine suction when the balls are on these seats.

Another feature is to introduce fuel free air on the engine side of the throttle butterfly of a two barrel carburetor and split and direct said air to form a spinning of said air around the bore of the manifold past the idle fuel inlet below the throttle valve during idle operation, the fuel free air in effect entering in a relatively tangential direction to the bore of the manifold below the throtle butterflies.

Other objects of the invention will be more particularly pointed out in the accompanying specifications and claims.

We have illustrated this invention in the accompanying drawings in which:

FIG. 1 is a top plan view of a portion of a carburetor incorporating one form of the invention.

FIG. 2 is a side elevation through section 2-2 of FIG. 1.

FIG. 3 is an enlarged top view partly cut away of an idle fuel valve portion of FIGS. 1 and 2.

FIG. 4 is a side view through section 44 of FIG. 1 but showing the ball off its seat.

FIG. 5 is an enlarged view of an alternate power device to the one shown in FIG. 2.

FIG. 6 is a top view of the air splitter of FIGS. 1 and 2.

In all figures like numerals of reference refer to corresponding parts.

In FIGS. 1, 2, 3, and 4 I have shown a carburetor body in a throttle body 11 carrying a throttle shaft 7 secured to throttle butterfly valves 6 and 6a by screws 7a. Throttle lever 5 is secured to throttle shaft 7 and is actuated by throttle rod 4 in the usual manner.

Idle fuel comes down passage 9 from the float bowl with the usual air bleed etc. common to many carburetors. Gasket 8 seals the carburetor 10 to the throttle body 11.

" ice A ball 13 rests on elastic seat 21 and is urged off its seat by cam 20a of cam shaft 20 when cam 20 is rotated so the flat intercepts the ball 13 to unseat it, as shown in FIG. 4. Ball 13a is likewise unseated at the same time as ball 13. Seals 20b may be used on each side of the cams on shaft 20 to reduce or eliminate fuel and'air leakage.

When balls 13 and 13a are unseated 'as when idling and cruising, idle fuel will flow down passage 9 past ball 13 to transfer ports 15 and 16 and on to idle jet orifice 17. The flow of idle fuel through idle orifice is controlled by idle needle 18a and idle screw 8. Adjustment is maintained by spring 19.

A solenoid 25 is actuated by energy through wires 26 and 27 and controlled in any suitable manner as by a governor switch and a throttle closed switch so the balls will be seated at closed throttle on deceleration at engine speeds above a predetermined minimum engine speed. The ball 13 will be unseated by cam 20a during idle, cruising, and acceleration to provide idle fuel during these operations. Fuel free air for idle engine operation enters through tube 30 into nozzle 31a through passage 31. Nozzle 31a is in the transfer port area 43 between and below (engine idle) butterflies 6 and 6a. A splitter 49 is secured by screw 50 and splits the fuel free 'air from nozzle 31a and directs it upward and around the manifold bores 11a and 11b below the butterflies 6 and 6a. This results in the idle air sweeping past the idle fuel entering through jet 17 and around the bore 11a clockwise as viewed in FIG. 1 and counter-clockwise in bore 11b to give improved mixing of the idle fuel and idle air. The butterflies 6 and 6a being closed at idle and decelerations, no fuel should flow from the main jets (not shown) of the carburetor as there is substantially no air flow past the main jets with closed butterflies 6 and 6a.

FIG. 5 shows an alternate method of operating cam shaft 20 to that shown in FIG. 2. Cam shaft 20 is attached to arm 29 and has spring 35 urging it to an upper position where cam 20a allows ball 13 to rest on seat 21. Diaphragm actuator 40 includes a housing, a diaphragm 53 secured to washers 42 and actuating rod 41. Spring 44 is adjusted by screw 45 and sealed by nut 46 and seal 47. Vacuum is supplied through line 48 in any wellknown manner so that ball 13 will be on its seat when the vehicle engine is decelerating with closed throttle at engine speeds above a predetermined minimum, The ball will be off its seat during idle, cruising, and acceleration operation to provide idle fuel during these operations.

Other controls of the idle to give different cycles of operation with the valves shown in this invention can be employed within the scope of this invention.

We have illustrated our invention in these various forms; however, many other variations may be possible within the scope of this invention.

To those skilled in the art to which this invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and description herein are purely illustrative and are not intended to be in any sense limiting.

We claim as our invention:

1. A carburetor for an engine comprising an intake manifold, a throttle valve in said intake manifold, an idle fuel passage, an idle fuel orifice in said manifold downstream of said throttle valve, said passage bypassing said throttle valve and connected to said idle orifice, a ball valve, a seat for said ball positioned upstream of said idle orifice, said ball valve stopping the flow of idle fuel when seated on said seat, a cam shaft, a cam on said shaft for unseating said ball, said ball and said cam shaft being located on the upstream side of said seat, means to operate i 4 a said cam and seat said ball valve in response to decelera- 2,07 8,481 4/1937 Chanavier 123-119 tion of the engine. 2,212,936 8/ 1940 Hoof.

2. A carburetor as defined in claim 1, in which there 2,752,132 6/1956 Nye. is at least two seals on said cam shaft, one of said seals 2,827,269 3/ 1958 Kittler. being on one side of said cam and the other of said seals 5 2,940,560 6/ 1960 Kline 251-438 being on the other side of said cam. FOREIGN PATENTS References Cited by the Examiner 1,03 5,173 4/ 1953 France.

UNIT ED STATES PATENTS 260,953 8/1949 Switzerland. 1,024,175 4/1912 BOW ROBERT F. BURNETT, Primary Examiner. 1,225,238 5/ 1917 Gray. HARRY B. THORNTON, HERBERT L. MARTIN,

2,008,657 7/ 1935 Deiller. RONALD R. WEAVER, Examiners. 

1. A CARBURETOR FOR AN ENGINE COMPRISING AN INTAKE MANIFOLD, A THROTTLE VALVE IN SAID INTAKE MANIFOLD, AN IDLE FUEL PASSAGE, AN IDLE FUEL ORIFICE IN SAID MANIFOLD DOWNSTREAM OF SAID THROTTLE VALVE, SAID PASSAGE BYPASSING SAID THROTTLE VALVE AND CONNECTED TO SAID IDLE ORIFICE, A BALL VALVE, A SEAT FOR SAID BALL POSITIONED UPSTREAM OF SAID IDLE ORIFICE, SAID BALL VALVE STOPPING THE FLOW OF IDLE FUEL WHEN SEATED ON SAID SEAT, A CAM SHAFT, A CAM ON SAID SHAFT FOR UNSEATING SAID BALL, SAID BALL AND SAID CAM SHAFT BEING LOCATED ON THE UPSTREAM SIDE OF SAID SEAT, MEANS TO OPERATE SAID CAM AND SEAT SAID BALL VALVE IN RESPONSE TO DECELERATION OF THE ENGINE. 